U.S. News & World Report put Princeton atop its list of the nation’s best universities last month. On Tuesday, the magazine declared Harvard best in the world — one of nine U.S. and three British universities listed ahead of the Ivy League school in New Jersey.

How can one U.S. university lead the national rankings as another one leads the world?

The answer is that U.S. News is introducing a new way to rank global universities, through analysis of the schools’ research prowess. Critics are likely to call the new global ranking as faulty as its domestic cousin. Both use subjective formulas. Both rely on data, such as reputational surveys, that prompt major debate within academia.

But rankings have become ingrained in recent years in higher education as students and faculty crisscross the country and the world. Before U.S. News jumped into global analysis, similar ranking efforts had arisen in the United Kingdom and Asia.

“When you have a marketplace, you need information in order for markets to function well,” said Ben Wildavsky, a former U.S. News education editor who is now director of higher-education studies at the Rockefeller Institute of Government, a unit of the State University of New York. Rankings, he said, are imperfect but “perform a useful function. They’re not going to go away. The challenge is to make them better.”

For its global analysis, U.S. News drew on data from Thomson Reuters InCites on various aspects of university research. Among them: global and regional reputations, scholarly publications, citations and impact, international collaboration, and awards of doctoral degrees.

Omitted from this formula are factors such as undergraduate admissions selectivity, graduation rates, alumni donations and some other measures typically included in the domestic ranking. That was by design. Uniform data to compare global universities, particularly the undergraduate experience, is scarce.

“This is about faculty productivity and prestige,” U.S. News Editor Brian Kelly said of the global ranking in a telephone interview Monday. “It is meaningful for certain things and not necessarily meaningful for other things. We get that. This is about big muscular research universities doing what research universities claim is their mission.”

U.S. News distributed the rankings to journalists Monday on condition that they not call universities for comment in advance of the release.

The list attempts to define the world’s 500 top schools from 49 countries. The United States dominates, with 134 schools listed, including eight of the top 10. The other two in the top 10 are the venerable British universities of Oxford and Cambridge. Germany has 42 schools on the list, followed by the United Kingdom with 38 and China with 27. (Hong Kong, a special administrative region of the People’s Republic of China, had an additional five.)

The global rankings offer a counterpoint to the U.S. News domestic list, with a formula that gives far greater recognition to strengths of certain public universities with high research profiles. The University of California at Berkeley, arguably the nation’s most prestigious public institution, ranks 20th on the domestic list but third on the global version. The University of California at Los Angeles ranks 23rd domestically but eighth globally.